From: Muchun Song songmuchun@bytedance.com
commit 585fc0d2871c9318c949fbf45b1f081edd489e96 upstream.
If a new hugetlb page is allocated during fallocate it will not be marked as active (set_page_huge_active) which will result in a later isolate_huge_page failure when the page migration code would like to move that page. Such a failure would be unexpected and wrong.
Only export set_page_huge_active, just leave clear_page_huge_active as static. Because there are no external users.
Link: https://lkml.kernel.org/r/20210115124942.46403-3-songmuchun@bytedance.com Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song songmuchun@bytedance.com Acked-by: Michal Hocko mhocko@suse.com Reviewed-by: Mike Kravetz mike.kravetz@oracle.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: David Hildenbrand david@redhat.com Cc: Yang Shi shy828301@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/hugetlbfs/inode.c | 3 ++- include/linux/hugetlb.h | 3 +++ mm/hugetlb.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-)
--- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -661,8 +661,9 @@ static long hugetlbfs_fallocate(struct f
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ set_page_huge_active(page); /* - * page_put due to reference from alloc_huge_page() + * put_page() due to reference from alloc_huge_page() * unlock_page because locked by add_to_page_cache() */ put_page(page); --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -506,6 +506,9 @@ static inline void hugetlb_count_sub(lon { atomic_long_sub(l, &mm->hugetlb_usage); } + +void set_page_huge_active(struct page *page); + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; #define alloc_huge_page(v, a, r) NULL --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1189,7 +1189,7 @@ bool page_huge_active(struct page *page) }
/* never called for tail page */ -static void set_page_huge_active(struct page *page) +void set_page_huge_active(struct page *page) { VM_BUG_ON_PAGE(!PageHeadHuge(page), page); SetPagePrivate(&page[1]);